U.S. Pat. No. 4,314,648 issued Feb. 9, 1982 and assigned to the assignee of this invention discloses a gravity feed shelf in which low friction tracks are utilized and which are formed by an extrusion process and which are homogeneous in nature with low friction material impregnated therein.
U.S. patent application Ser. No. 510,495 filed July 5, 1983, now U.S. Pat. No. 4,470,943, and owned by the assignee of this invention discloses and claims a process for forming a low friction plastic track which is homogeneous from a mixture of high impact polystyrene and organo polysiloxane fluid such as dimethyl, diethyl, and phenylmethyl siloxane and related copolymers.